Chuck



7, 1943. F. c. SNYDER 2,327,074

CHUCK Filed July 26, 1940 INVENTOR' /9 Fwy CSNYDER BY if I .34 TTORNPatented Aug. 17, 1943 OFFICE CHUCK Floyd C. Snyder, Akron, OhioApplication July 26, 1940, Serial No. 347,622

(Cl. 144 s2) 4 Claims.

This invention relates to chucks, and more especially it relates toscrew-holding chucks for use with power operated screw drivingapparatus, either of the stationary or the portable type.

Chucks of the character mentioned are provided for holding a screw andkeeping it in proper contact with the rotary bit or blade of the screwdriver while the screw is being driven. Such chucks heretofore providedusually have yieldingly engaged and held the screw until the latter hasbeen substantially set up, then been retracted out of engagement withthe screw by being overcome by forces set up as the screw becomes fullydriven. In some cases the chuck has consisted of a pair of leaf springshaving free ends engaging the screw to be driven. In other cases thechuck has comprisedmovable jaws held in screw-engaging position by anendless coiled spring. Another type of chuck has employed spring-backedball detents. 'Thus the screws frequently were held too loosely forefllcient operation due to weakening of the spring members of the chucksas the result of continued use.

The chief objects of this invention are to provide an improved chuck forscrew driving machines; to provide a chuck of the character mentionedthat will hold a screw positively and firm-- 1y; to obviate the use ofyielding members such as springs in screw-holding chucks; and to providein a novel and superior manner for effecting release of the screws asthey become fully set up. Other objects will be manifest as thedescription proceeds.

Of the accompanying drawing:

Figure 1 is a fragmentary sectional view of a screw driving apparatuscomprising the improved chuck, and a screw held therein;

Figure 2 is a section on the line 22 of Fig. 1, on a larger scale,showing the parts with relation to the work as the screw is about toenter the latter. I

Figure 3 is a view of the lower portion of the structure shown in Fig. 2showing the relative positions of the elements as the screw enters thework; 7

Figure 4 is a view similar to Fig. 3 showing the screw fully threadedinto the work; and

Figure 5 is a section on the line 55 of Fig. 2. Referring to thedrawing, particularly Fig, 1-

thereof, there is shown a portion of a screw dr'1v ing machinecomprising a power driven spindleg' It! in which is mounted a screwdriver bit ll, 1

Cir

ing a magazine or chute [3 by means of which The improved chuckcomprises a tubular quill 16 that is secured to slide [2 by means of setscrew ll, the quill being formed with an axial bore 18 in which thescrew driver bit II is re ceived. Slidably mounted upon the quill I6 isa sleeve [9 arranged forlimited axial movement thereon. The sleeve [9 isformed with a longitudinally extending slot 29 through which freelyextends a screw 2| that is threaded into the quill [6, the arrangementbeing such that the screw prevents angular movement of the sleeve on thequill and limits the axial movement of the sleeve relatively of thequill. Normally the sleeve 19 extends somewhat beyond the lower or freeend of the quill, said sleeve being yieldingly urged to this position bya compression spring 22 that is mounted upon the quill between the upperend of sleeve 1 9 and a shoulder-'23 formed on the quill at the regionof the latter adjacent slide [2. The lower end portion of sleeve IS, onthe side thereof that confronts the magazine I3, is tangentially cutaway at 24 to expose the quill l5 therein, and the portion of the quillthus exposed is formed with a central longitudinal slot 25 at its lowerend, the wall of the quill at the upper end of slot 25 being out back asshown at 26, Fig. 1, at each side of said slot. The arrangement is suchthat the slot 25 constitutes, in effect, a continuation of the slot inthe bottom of the magazine [3, so that screws l4 released from thelatter may enter the bore I8 of quill [6. Release of screws M from themagazine is efiected by movement of the slide l2 relatively of thespindle l0, and the screws move into the quill [6 of the chuck while thelatter and the screw driver bit II are in the relative positions shownin Fig. 1, in which positions the lower end of the bit does not obstructthe slot 25 of the quill, {It is necessary that means be provided forretaining a screw [4 in the lower end of the quill after it has beendeposited therein and to this end the quill is formed with a plurality,herein shown as three in number, of radial bores 23, 2B

disposed near the lower end thereof. Mounted in the bores 28 arerespective hardened, polished steel balls 29, such as ball bearings, theinner ends of the bores 28 being locally constricted or peened over toprevent the balls from passing therethrough completely into the axialbore l8 of the quill. As shown in Figs. 2, 3 and 5, the balls 29normally project partly into the axial bore of quill l6 and thusobstruct the passage of a screw from the lower end thereof by engagementwith the head of the screw. This condition obtains at all times that thesleeve I9 is in its lowermost position on the quill under the impetus ofspring 22, the sleeve thereby closing the outer ends of the bores 28.The lower end of sleeve [9 is counterbored and countersunk at 30 so asto be locally of substantially larger inside diameter than the outsidediameter of the quill. Normally the counterbore 30 is disposed beyondthe radial bores 28 of the quill, but under some circumstances thesleeve 19 'is moved axially of the quill l6 against the force of spring22, to bring the counterbore 30 opposite the outer ends of bores 28,with the result that balls 29 are enabled to move radially outwardly insaid bores a limited distance so they no longer project into the bore I8of the quill, as is best shown in Fig. 4. In this position the balls nolonger obstruct the passage of the head of screw l4 through said bore.

The operation of the chuck as described is fully automatic in operationas will be apparent from reference to Figs. 2, 3 and 4 wherein a typicaloperative cycle of the apparatus is shown. Said figures show 'how thescrew driver operates to join two work-pieces 32, 33 by means of a screwit, said work-pieces resting upon a support 34, the work-piece 32 beingformed with an aperture 35 and the work-piece 33 being formed with ascrew-receiving threaded bore 35 in alignment withsaid aperture 35.After the slide 12 and magazine [3 have been moved relatively of therotating bit I I to deliver a screw M to the chuck, as shown in Fig. 1,said elements are moved back to the normal operatingposition shown inFig. 2 wherein the bit engages the driving slot of the screw, the latterbeing securely held in position by the balls 29. The apparatus is thenbrought into juxtaposition to the work, the screw [4 is passed throughaperture 35 of work-piece 32 and threaded into bore 35 of work-piece 33.As the screw moves axially into bore 36, the chuck holding the screwmoves toward work-piece 32, and engages the latter, as shown in Fig. 3,before the screw is fully set up. Thereupon axial movement of the sleeve[9 ceases, but the bit H and quill 46 continue to move axially, with theresult that the radial bores 28 of the quill move into the region of thecounterbore 33 of the sleeve, and the balls 23 in said bores are forcedoutwardly, out of the path of the head of screw 14, as shown in Fig. 4.Thus the bit H is enabled to drive the screw axially to its fully set upposition, during which the bit may move axially relatively of the quilla short distance after the quill engages the work-piece 32. v

The chuck is fully automatic in its operation,

it holds a screw firmly preparatory to the screw driving operation, andit achieves the other advantages set out in the foregoing statement 0!objects.

Modification may be resorted to without departing from the spirit of theinvention or the scope thereof as defined by the appended claims.

What is claimed is:

1. In a chuck for screw driving apparatus, the combination of a tubularquill positioned about the screw driver bit and movable axiallyrelatively thereof, radially extending bores through the lower endportion of said quill, respective ball detents in said bores adapted toproject partly into the axial bore of the quill to retain a screwtherein, the inner ends of said radial bores being slightly constrictedto prevent the balls from completely passing therethrough, and a sleeveslidably mounted on the quill and having limited axial movementrelatively thereof, said sleeve extending over said radial bores andnormally engaging said balls to hold them positively partly within theaxial bore of the quill, said sleeve having a local region of increasedinside diameter, which region is disposed opposite the outer ends of theradial bores of the quill in one position of the sleeve to enable theball detents to move outwardly in their bores and thus to release ascrew, said sleeve normally extending beyond the lower end of the quillso as to be moved relatively of the latter by engagement with the workbefore the screw is fully driven.

2. A combination as defined in claim 1, including a compression springurging the sleeve toward normal position.

3. In a chuck for screw driving apparatus, the combination of a tubularquill positioned about a screw driver bit and movable axially relativelythereof, radially extending bores through the lower end portion of saidquill, the inner ends of said bores being somewhat constricted,respective ball detents in said bores adapted to project partly into theaxial bore of the quill to retain a screw therein, a sleeve slidablymounted upon said quill and normally engaging said balls and positivelyholding them partly within the axial bore of the quill, said sleeveformed with a longitudinally extending slot, a'member extending throughsaid slot and fixed in the quill for limiting axial movement of thesleeve relatively of the quill and for preventing relative angularmovement therebetween, a compression spring urging the sleeve toward anormal position wherein the lower end of the sleeve projects beyond thequill, the said projecting portion of the sleeve being of increasedinside diameter, which region is opposite the outer ends of the radialbores 0f the quill when the sleeve is moved against the force of saidspring to an alternative position, thereby enabling the ball detents tomove outwardly in their bores to release the screw.

4. A combination as defined in claim 3 in which the sleeve and quillhave aligned longitudinally extending openings in one side thereof toenable screws to be passed into the axial bore of the quill above theball detents therein.

FLOYD C. SNYDER.

